Big chunks of buildable land in and around Portland are hard to come by anymore. But 60-plus contiguous acres along the Willamette River near downtown are quietly taking shape as one of the most intriguing and promising sites for development here or anywhere.

About 33 acres are owned by the barge-building Zidell family. Those acres are bound by 20 acres to the north and 10 acres to the south, all owned by Oregon Health & Science University. The divided OHSU parts are already spoken for, with OHSU's Center for Health and Healing situated at the base of the aerial tram and a new OHSU-Oregon University System Collaborative Life Sciences Center now under construction to the north.

But in the middle is an expanse of dirt owned by the Zidells. And it has finally taken shape with the release this week of a development plan calling for up to 30 buildings that will concentrate residential housing atop ground-floor retail shops and restaurants while also comprising offices, hotels, even a grocery store.

The property was until recently a hammered industrial mess, with no city grid to define it. And so everything is up for grabs -- down to the very shape and size of new city blocks that may hold odd-shaped buildings and a few curvy streets. Among the go-go firms already expressing interest in building in the Zidell waterfront area is M Financial Group, a wealth management firm based in the Pearl District's Brewery blocks, The Oregonian's Elliot Njus reported.

But this has been a long time coming. It follows years of negotiations with the city and the Portland Development Commission, and $20 million worth of environmental cleanup that involved capping acres of tainted river sediments. What's evident from the development concept is that the Zidells see not just a robust business opportunity in their land but a legacy-builder for a family that views itself as old Portland.

Matt French, who graduated from Lincoln High School and is the great-grandson of the firm's founder, Sam Zidell, intones as much when he says, "We've worked this site for 60 years, and with that comes a sense of responsibility and stewardship." He's more animated yet in saying, "With this, we get to completely reimagine what an urban neighborhood could be. The buildings may change somewhat, but what won't change is the spirit of the plan."

Amen. Let there be more structures like the first building to be green-lighted: a 118-unit apartment midrise near the foot of the Ross Island Bridge and proximate to the tram and OHSU's center for healing. Aside from its unconventional curved lines and ideal location, it will have the uncommon attribute of being both new and affordable -- small units for students and OHSU staff as the medical campus expands.

Significantly, more than 25 percent of the 33 acres will be retained as open space in the form of parks and a 100-foot-wide greenway lining the waterfront and connecting to the riverwalk in downtown Portland. Docks that help people get onto the Willamette River will be constructed, as well, and they will surely be crowded as new barges are launched from Zidell's nearby marine yard, to remain open and a source of family wage jobs.

Nothing ever is perfect. Development, forcing compromise every step of the way, often fails the imagination. But if Portlanders were to look for a surge of promising activity in an urban renewal area into which roads, trains, buses, and a tram converge, this is it. It's hard to imagine, but when done the fishing might be good, too.

OHSU, which has much at stake in the success and configuration of the Zidells' development, is delighted so far. So, it seems, are the Zidells, who've struggled to find an original development conception while staying in the barge business.

Portlanders, meanwhile, can enjoy the assurance that their last big piece of waterfront will look cool and be cool, even quirky, as it becomes a dynamic and more engaging part of the city.